Shoe

ABSTRACT

Provided is a walkable shoe having a glass-like appearance. The shoe has a heel portion, a sole portion provided on the heel portion, and an upper portion provided on the sole portion; wherein the heel portion and the sole portion are made almost entirely of an organic glass, and the upper portion is made almost entirely of an organic glass.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a shoe.

Description of Related Art

Generally, a shoe includes an upper portion, a sole portion, and a heel portion. Among various kinds of existing shoes, there are high-heels for women with a high heel portion.

Traditionally, many high-heels have been proposed that emphasize comfort and safety when worn. In order to improve comfort when worn and to make the high-heels easy to walk in, there are many high-heels that have been proposed in which at least the upper portion is made of a soft member such as leather or soft vinyl.

Japanese Patent Application Patent JP 2015-130930 A (PTL 1) describes a high-heel shoe having an insole provided with a plurality of recessed grooves in a front end portion and a rear end portion in order to prevent a foot from slipping forward in the shoe.

CITATION LIST Patent Literature

PTL 1: JP 2015-130930 A

BRIEF SUMMARY OF THE INVENTION

Generally, hard members such as glass, acrylic resin, PETG resin and the like have transparency or translucency, metallic or mineral gloss, and beautiful appearance.

Therefore, by using such a hard members for shoes, it is possible to obtain shoes that are aesthetically superior. However, shoes made of hard members do not have flexibility, so are unable to follow the deformation of the foot during walking, and due to the properties of hard members, it is difficult to put hard members into practical use.

Therefore, an object of the present invention is to provide a shoe made of a hard member and capable of being walked in while having a glass-like aesthetic appearance.

The shoe according to one aspect of the present invention is a shoe that includes a heel portion, a sole portion provided on the heel portion, and an upper portion provided on the sole portion; wherein the heel portion and the sole portion are made almost entirely of an organic glass, and the upper portion is made almost entirely of an organic glass.

The above-described shoe may have a plurality of reflective planes (facets) on at least a part of the surface thereof.

At least part of the sole portion and the inside of the upper portion is provided with an insole having a cushioning property to compensate for a gap generated between the shoe and a foot of a wearer.

The manufacturing method according to an aspect of the present invention may have a step of integrally molding the heel portion and the sole portion with a synthetic resin, a step of integrally molding the upper portion with a synthetic resin, and a step of joining the upper portion with the heel portion and the sole portion that are integrally molded.

The manufacturing method of a shoe according to an aspect of the present invention includes a step of integrally molding the heel portion and the sole portion with a synthetic resin, a step of molding the rear portion of the upper portion with a synthetic resin, a step of molding a main body portion that is a portion other than the rear portion of the upper portion with a synthetic resin, a step of joining the main body portion of the upper portion with the heel portion and the sole portion that are integrally molded, and a step of connecting the rear portion to the main body portion.

With the present invention, it is possible to provide a walkable shoe made of a hard member having a glass-like aesthetic appearance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a shoe according to a first embodiment of the present invention.

FIG. 2 is a side view of a shoe according to a first embodiment of the present invention.

FIG. 3 is a perspective view of a shoe according to a first embodiment of the present invention.

FIG. 4 is a perspective view of a shoe according to a first embodiment of the present invention.

FIG. 5A is a cross-sectional view taken along line A-A in FIG. 4.

FIG. 5B is a cross-sectional view taken along line B-B in FIG. 4.

FIG. 5C is a cross-sectional view taken along line B-B in FIG. 4.

FIG. 6A is a perspective view of a shoe according to a second embodiment of the present invention.

FIG. 6B is a transverse cross-sectional view taken along line A-A in FIG. 6A.

FIG. 7A is a perspective view of a shoe according to a third embodiment of the present invention.

FIG. 7B is a cross-sectional view taken along line A-A in FIG. 7A.

FIG. 8 is a transverse cross-sectional view of a shoe according to a fourth embodiment of the present invention.

FIG. 9A is a perspective view of a shoe according to a fifth embodiment of the present invention.

FIG. 9B is a cross-sectional view taken along line A-A in FIG. 9A.

FIG. 10 is a perspective view of a shoe according to a sixth embodiment of the present invention.

FIG. 11 is a perspective view of a shoe according to a seventh embodiment of the present invention.

FIG. 12 is a perspective view of a heel portion of a shoe according to an embodiment of the present invention.

FIG. 13 is an explanatory view of a first manufacturing method of a shoe according to an embodiment of the present invention.

FIG. 14A is a partially enlarged view of a first manufacturing method of a shoe according to an embodiment of the present invention.

FIG. 14B is a partially enlarged view of a first manufacturing method of a shoe according to an embodiment of the present invention.

FIG. 15 is a perspective view illustrating a first manufacturing method of a shoe according to an embodiment of the present invention.

FIG. 16 is a perspective view illustrating a second manufacturing method of a shoe according to an embodiment of the present invention.

FIG. 17 is a perspective view illustrating a third manufacturing method of a shoe according to an embodiment of the present invention.

FIG. 18 is a side view of a shoe according to an eighth embodiment of the present invention.

FIG. 19 is a use diagram of a shoe according to an embodiment of the present invention having a sock.

FIG. 20 is a perspective view illustrating a shoe according to a ninth embodiment of the present invention, and explains a manufacturing method thereof.

FIG. 21 is a perspective view illustrating a shoe according to a ninth embodiment of the present invention, and explains a manufacturing method thereof.

FIG. 22 is a partially enlarged view of FIG. 20.

FIG. 23 is a perspective view illustrating a shoe according to a tenth embodiment of the present invention, and explains a manufacturing method thereof.

FIG. 24 is a partially enlarged view of FIG. 23.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, examples of embodiments of the present invention will be described below with reference to the drawings. Note that in the following embodiments, the same or similar constituent elements are denoted by the same reference numbers, and an explanation thereof may be omitted. In addition, in each of the embodiments, characteristic constituent elements are mainly described, and the constituent elements of other embodiments may be included.

First Embodiment of the Present Invention

FIG. 1 is a perspective view of a shoe according to a first embodiment of the present invention. Note that the left side in FIG. 1 is referred to as the front direction of the shoe or the toe side, and the right side is referred to as the rear direction of the shoe or the heel side. The direction connecting the toes and the heel is called the length direction, and the direction perpendicular to that direction is called the width direction.

As illustrated in FIG. 1, the shoe 1 of the present embodiment is a high-heel for women, and includes a heel portion 2, a sole portion 3, and an upper portion 4. The heel portion 2 stands approximately perpendicular to the ground contact surface, so that the heel portion of the foot is positioned higher than the toe portion of the foot of the wearer.

The sole portion 3 is joined to the upper surface of the heel portion 2 on the heel side of the foot. The upper portion 4 has an insert opening for putting a foot into and is joined to the sole portion 3 at the peripheral edge portion of the upper surface of the sole portion 3.

The heel portion 2, the sole portion 3 and the upper portion 4 are formed of transparent hard members. The hard members may be translucent and may have a metallic or mineral gloss. The mineral gloss may have a pattern such as a marble pattern. The hard members may have a color on at least a part of the surface. Alternatively, the hard members may have an iridescent luster on at least a part of the surface.

In this embodiment, as illustrated in FIG. 1, the hard members have a plurality of reflective planes (facets) on the surface so as to emphasize the aesthetic appearance. The reflective planes are provided on the entire surface of the upper portion 4, the side surface of the sole portion 3, and the surface of the heel portion 2, and are provided so as to receive light and reflect light in a sparkly manner. The reflective planes are provided on the entire surface of the shoe so that the upper portion 4, the sole portion 3 and the heel portion 2 are seen as continuous, and even though the upper portion 4, the sole portion 3 and the heel portion 2 may be formed of separate parts, it is possible to achieve an effect of appearing as a single part. Incidentally, in the example of FIG. 1, the upper portion 4 is also made of a hard member, however the upper portion 4 may be made of ordinary leather or a soft member instead of the hard member. In that case as well, by forming only the heel portion 2 and the sole portion 3 of hard members, it is possible to exhibit sufficient aesthetic appearance. In addition, it is also possible to provide a reflective plane only on the surface of the heel portion 2. In that case, features can be given in terms of design by emphasizing the heel portion 2.

For the hard members, for example, glass, organic glass (acrylic resin, polycarbonate resin, PETG resin (glycol modified polyethylene terephthalate)), or the like can be used.

Moreover, the hard members may be an artificial material with the main component being an acrylic resin or polyester resin, such as artificial marble. As a further example is soft acrylic having improved impact resistance with a polymer obtained by mixing a rubber component (IR) with acrylic resin (PMMA), for example. Soft acrylic is a flexible thermoplastic acrylic resin.

Reference number 5 indicates a decoration attached to the upper portion 4. The decoration will be described later.

FIG. 2 is a side view of a shoe 1 according to a first embodiment of the present invention.

The shoe 1 has a plurality of decorations 5, and in the example of FIG. 2, a plurality of decorations 5 are attached to a bump portion 7 (a portion in front of the insert opening of the shoe), the heel portion, and the side portion (portion on the side of the insert opening) of the upper portion 4.

Decorations 5 may also be attached to the heel portion 2 and the sole portion 3. Decorations 5 may be colorless and transparent gemstones like diamonds, colored jewels such as sapphires and emeralds, pearls, or imitations of these, ribbons formed of resin, objects with animal motifs such as butterflies and the like. In addition, the decorations 5 may be formed of the same material as the hard members. The decorations 5 may be made of the same material as the hard member constituting the shoes, and made so as to have different colors.

A decoration 5 is attached to the upper portion 4 via an attachment portion 12. The attachment portion 12 becomes the base of the decoration 5 and is fixed to the upper portion 4 by adhesion, fusion bonding, or integral molding. The decoration 5 is attached to the attachment portion 12 by fitting, a slide coupling, screwing, bonding, or the like. Note that the decoration 5 may also be formed integrally with the upper portion 4.

On the front side portion of the sole portion 3, a downwardly convex curved portion 6 is provided. The curved portion 6 is provided at a portion of the sole portion 3 where the area near the metatarsal bone comes in contact in order to stabilize the area near the metatarsal bone of the wearer. It is possible to prevent the foot from slipping by the curved portion 6, and to reduce the load on the area from the tip of the toes to the base of the toes and the front of the sole where much of the body weight is applied.

Moreover, on the inner side of the bump portion 7 of the upper portion 4, a bump portion insole 10 made of a flexible material is provided. The bump portion insole 10 can reduce the gap between the upper portion 4 and the foot of the wearer, and allow the foot of the wearer to move somewhat inside the shoe 1 while walking. The bump portion insole 10 is preferably made of a transparent material.

The thickness of the sole portion 3 is arbitrary, but the maximum thickness is 8 mm to 50 mm, and preferably 10 mm to 20 mm.

FIG. 3 is an exploded perspective view of the shoe 1 in which the heel portion 2 and the sole portion 3 are integrally formed.

In FIG. 3, the base portion 11 that includes the heel portion 2 and the sole portion 3 is integrally molded, and the upper portion 4 is attached to the base portion 11. The integral molding will be described later.

FIG. 4 illustrates a perspective view of a shoe 1 provided with the insole of the present invention.

The shoe 1 preferably has a plurality of insoles. In the example of FIG. 4, a bottom insole 9 is attached to the front of the sole portion 3 and a side insole 13 is attached to the side portion of the upper part 4. Insoles can be attached to a plurality of locations on the sole portion 3 and the inner surfaces of the upper portion 4.

The insoles are flexible members having a cushioning property, for example, a shock absorbing polymer gel (gel), an elastomer or silicone rubber having a hardness of 10 to 30 degrees, or the like is suitable. Although the insoles may have a color on a part of the surface, by making the insoles the same color as the sole portion 3 and the upper portion 4, or making the insoles a transparent or mirror surface, the insoles are integrated with the shoe 1, which is preferable.

Here, the hardness is a “durometer hardness” which is generally widely used because the measuring machine is simple. “Durometer hardness” is a method of pushing a non-sharp needle (pushing needle, indenter) on the surface of the object to be measured, then measuring the amount of deformation and digitizing it; where a spring is used as a force to push the needle. Being standardized in accordance with JIS K 6253-3, there is a Type A, Type D, Type E and Type AM durometer, and the selection is as follows:

-   -   Type A is used in the case where the hardness is less than 20         with a type D durometer.     -   Type E is used in the case where the hardness is less than 20         with a type A durometer.     -   Type D is used in the case where the hardness is greater than 90         with a type A durometer.     -   Type AM is used in the case of a thin test specimen (thickness         is less than 6.0 mm).         The hardness in the present description and in the claims is the         value measured with a durometer of the type selected as         described above.

Moreover, the insole may be a foam material such as a polyurethane foam. Furthermore, synthetic leather or the like may be used. In the case where the inside of the shoe has an effect of appearing transparent, it is preferable that the member be a transparent material. On the other hand, when coating or applying a pattern to the inner surface of a shoe, it is not always necessary to be a transparent body.

The bottom insole 9 and the side insole 13 compensate for gaps generated between the shoe and the wearer's foot, and by having a cushioning property, the shoe fits the wearer's foot during rest, and allows for movement of the wearer's foot when walking. This will be explained with reference to FIG. 5.

FIG. 5A is a cross-sectional view of the shoe 1 in a portion indicated by the arrow A-A in FIG. 4, and FIGS. 5B and 5C are cross-sectional views of the shoe 1 in a portion indicated by the arrow B-B in FIG. 4.

Generally, when wearing high heels, weight is applied more toward the front of the sole of the foot, and pressure tends to be applied to the vicinity of the cuboid bone from the fifth metatarsal bone that spreads widely in the width direction, so pain in the surrounding area is likely to occur. As illustrated in FIG. 5A, by providing the side insole 13 made of a flexible member on the side portion of the upper portion 4, it is possible to absorb the pressure received in the vicinity of the cuboid bone from the fifth metatarsal bone, and relieve the pain.

In addition, when wearing high heels, the entire foot slides forward and supports the body near the base of the toes, so it becomes easy for a load to be applied to the joints near the base of the toes, and pain is likely to occur. As illustrated in FIG. 5B, it is possible to prevent sliding by providing a recess portion 8 on the front side of the sole portion 3, and providing the bottom insole 9 there. As illustrated in FIG. 5C, by providing the bottom insole 9 made of a flexible member on the front side of the sole portion 3, sliding of the foot in the forward direction can be suppressed, and furthermore, the load received in the vicinity of the base of the toes can be reduced.

Note that, an uneven portion for preventing the bottom insole 9 from sliding may be provided in the portion where the bottom insole 9 is arranged.

Incidentally, the bottom insole 9 may be provided in the heel portion of the foot or in another portion where a gap occurs between the shoe and the wearer's foot.

Moreover, instead of providing the insoles, the sole portion 3 and the upper portion 4 may be provided with convex portions or concave portions matching the outer shape of the wearer's foot.

Second Embodiment of the Present Invention

FIG. 6A is a perspective view of a shoe 1 according to a second embodiment of the present invention, and FIG. 6B is a transverse cross-sectional view of a portion indicated by an arrow A-A in FIG. 6A.

A through hole may be provided in the upper portion or the like of the shoe, and an insole may be fitted into that through hole. Such an insole is called a “fitted insole”. For a portion exposed to the inside of the shoe, the fitted insole can have a function as the insole or the inner surface of the shoe, and for the portion exposed to the outside of the shoe, the fitted insole can have a decorative element or a functional element. The second embodiment of the present invention has an insole that is this kind of fitted insole and that provides a decoration such as color or the like on the outside surface of the shoe.

The same parts as those of the first embodiment are denoted by the same reference numerals, and redundant explanations are omitted except when necessary. In this regard, the same applies to the explanations of other embodiments that follow.

In the shoe 1 a in FIG. 6A and FIG. 6B, the sole portion 3 has a bottom insole 9, and the side portion of the upper portion 4 has a through hole 14 and a fitted insole 15.

The fitted insole 15 can be attached to the sole portion 3, or can be attached at a plurality of locations.

As illustrated in FIG. 6A and FIG. 6B, the fitted insole 15 has necessary flexibility and is attached by being fitted in the through hole 14. When the fitted insole 15 is fitted in the through hole, the outer surface of the fitted insole 15 is exposed to the outside of the shoe through the through hole 14 provided in the side portion of the upper portion 4 so as to be visible.

The fitted insole is a relatively rigid member; for example, a material such as elastomer, silicon rubber, polypropylene, nylon, vinyl chloride, foam material such as polyurethane foam, and the like is suitable.

The fitted insole 15 has a decorative part 16 on a part of outer surface thereof. At least a part of the outer surface of the fitted insole 15 is given a color or iridescent luster on the decorative part 16. The decorative part 16 may be semi-transparent, metallic, or a mineral gloss. The mineral gloss may have a marble-like marble pattern, for example. In addition, the decorative part 16 may be formed by adhering inorganic glass, organic glass (acrylic resin, PETG resin, and the like) to the fitted insole 15.

Although the entire fitted insole 15 may be formed entirely of a member having the same physical properties, the inner portion of the shoe may be made to have flexibility.

Third Embodiment of the Present Invention

In a third embodiment of the present invention, a decorative portion is provided on a portion of a fitted insole that is exposed to the outside of the shoe.

FIG. 7A is a perspective view of a shoe 1 b according to a third embodiment of the present invention, and FIG. 7B is a transverse cross-sectional view of a portion indicated by an arrow A-A in FIG. 7A.

As illustrated in FIG. 7A, a plurality of through holes 18 and fitted insoles 19 are attached to the side portion and the bump portion 7 of the upper portion 4 b, and the fitted insole 19 has a decoration 20 on the outer surface.

In the present embodiment, a joint receiving portion 17 is provided on the front side portion of the sole portion 3. The joint receiving portion 17 has a concave shape matching with the joints of the toes of the wearer's foot, and is recessed in the portion where the joints of the toes of the wearer are positioned.

A joint receiving portion 17 is preferably provided corresponding to each toe in order to further prevent the foot from sliding. In addition, the bottom insole 9 may be attached to the joint receiving portion 17.

The decoration 20 attached to the outer surface of the fitted insole 19 is made of colorless transparent jewel like diamond, colored jewel like sapphire or emerald, pearl, or imitations of these, or is made of resin and has a motif such as a heart mark, star marks, ribbons, animals such as butterflies, and the like. The decoration 20 may be formed of a hard member of the same quality as the sole portion 3 or the upper portion 4, or may be a hard member of the same quality and different in color.

As illustrated in FIG. 7B, the fitted insole 19 is fitted in the through hole 18 provided in the side portion of the upper portion 4 and attached so as to be seen from the outside of the shoe. The decoration 20 is attached to the fitted insole 19 by fitting, slide coupling, integral molding, screwing, adhesion or the like. By replacing the decoration 20, it becomes possible to coordinate the decoration 20 with various situations.

Fourth Embodiment of the Present Invention

In a fourth embodiment of the present invention, a fitted insole is provided in a sole portion of a shoe. The fitted insole provided in the sole portion of the present embodiment is provided with a portion having an insole function with respect to the inside of the shoe, and a portion having a function of stopping slipping of the outside of the bottom surface of the shoe.

FIG. 8 is a transverse cross-sectional view in the width direction of a shoe according to a fourth embodiment of the present invention.

In the example in FIG. 8, plural sole-fitted insoles 21 are attached to through holes 22 provided in the sole portion 3 c. The through holes 22 may be provided at arbitrary positions on the front side portion of the sole portion 3 c, however they may also be provided at portions that come in contact with the wearer's toe joints.

In the case where the through holes 22 are provided at portions that come in contact with the toe joints of the wearer, the end portions on the wearer side of the sole-fitted insoles 21 act as joint receiving portions 24 that reduce the load received by the base and vicinity of the wearer's toes, and further suppress the wearer's foot from sliding forward. In the case where the through holes 22 are provided at arbitrary positions of the front side portion of the sole portion 3 c, the ground-side end portions of the sole-fitted insoles 21 function as slip-preventing portions 23 with respect to the ground. These slip-preventing portions 23 can prevent slipping when walking on an unstable surface, such as on a wet floor or the like.

Fifth Embodiment of the Present Invention

In a fifth embodiment of the present invention, an opening or notch is provided in a side portion of an upper portion of a shoe.

FIG. 9A is a perspective view of a shoe 1 d according to a fifth embodiment of the present invention, and FIG. 9B is a transverse cross-sectional view taken along the arrow A-A in FIG. 9A.

The shoe 1 d has a notch 25 in the upper portion 4 d near the fifth metatarsal bone of the wearer.

The notch 25 may be provided in the upper portion 4 d in vicinity of the first metatarsal bone (arch portion) or in the vicinity of both the fifth metatarsal bone (the outer portion on the opposite side of the arch) and the first metatarsal bone (arch portion).

By providing the notch 25, the foot of the wearer appears to be long and the aesthetic appearance of the shoe 1 d is further emphasized. In addition, the upper portion 4 d is formed of a hard member, so by providing the notch 25, the insert opening is widened and even in the case of forming the shoe 1 d of a hard member, the shoe is easy to put on.

Note that an opening portion may be provided instead of the notch 25.

Sixth Embodiment of the Present Invention

In a sixth embodiment of the present invention, a strap is provided on an upper portion of a shoe.

FIG. 10 illustrates a perspective view of a shoe 1 e according to a sixth embodiment of the present invention.

In the example illustrated in FIG. 10, the shoe 1 e has a fastening portion 26 and a strap 27 at a high position of an insert opening of the upper portion 4 e (in-step strap). By holding down the wearer's foot at the portion near the ankle, the strap 27 can increase the sense of stability when the shoe is worn.

In addition, the fastening portion 26 and the strap 27 may be attached to the front side of the upper portion 4 (Mary Jane style). The strap 27 may be fastened so as to wind around the ankle portion once (ankle strap), or may be combined with a strap extending from the vicinity of the center of a bump portion 7 to form a T shape (T strap).

The strap 27 may be attached by combining the above-described various straps. By attaching more than one strap, stability is increased even more.

Here, the fastening portion 26 has a shape that allows the strap 27 to pass through a hole provided in the upper portion 4, however it may be a protrusion for hooking and fastening the strap 27, or may be a screw hole for fastening the strap 27 by screws.

Seventh Embodiment of the Present Invention

The seventh embodiment of the present invention is provided with an illuminator, a sound generator, or the like.

FIG. 11 is an exploded perspective view of a shoe if according to a seventh embodiment of the present invention.

In the shoe 1 f, a heel portion 2 and a sole portion 3 f are integrally molded. A concave portion 28 is provided in a part of the upper surface of the sole portion 3 f, and a circuit board 29 incorporating a sensor and a battery is provided in the concave portion 28. A conductive wire 30 is connected to the circuit board 29, and the conductive wire 30 is arranged in a groove portion extending to in front of the recessed portion 28. A display device 31 is provided at the tip of the conductive wire 30. A cover (insole) 32 is attached so as to cover the concave portion 28, and the upper portion 4 is joined to the upper surface of the cover (insole) 32.

On the circuit board 29, when the sensor senses a vibration generated when the wearer walks, or senses surrounding sound or light, the display device 31 emits light through the conductor 30. Note that, in consideration of durability, the display device 31 is preferably an LED. The light generated from the display device 31 may blink or the color may change with the lapse of time. Here, one display device is shown, however, a plurality of display devices may be used for a display such as in illumination.

Moreover, instead of the conducting wire 30, a glass fiber may be used, and by causing the circuit board 29 to emit light by LEDs or the like, the light may be guided by the glass fiber to emit light from the tip thereof. Furthermore, a structure is possible in which grooves and ribs for guiding light to the sole portion 3 f and the upper portion 4 may be provided, and by performing a fine cutting process or a blasting process to the inside of the grooves or the ribs, light can be easily diverged.

The sole portion 3 f of the shoe if of the present embodiment is preferably made of a transparent or translucent hard member, and in this case, light is transmitted inside the sole portion 3 f and is radiated to the surroundings from the side surface or the front surface, so a visually beautiful effect can be obtained.

Instead of the conducting wire 30 and the display device 31, a device that emits sound, or a device that plays music using, for example, a memory card, or a device that wirelessly plays music from the outside may be provided.

Moreover, light may be controlled wirelessly.

In FIG. 11, the circuit board 29, the display device 31 and the like are incorporated in the sole portion 3 f and the upper surface thereof is secured by the cover (insole) 32. However, the circuit board 29 and the display device 31 may be incorporated in the heel portion 2 or the upper portion 4.

Moreover, by using solar cells, wireless charging such as by electromagnetic induction or the like, it is possible to make battery replacement unnecessary.

[Heel Portion of the Present Invention]

A seventh embodiment of the present invention has a replaceable heel portion.

FIG. 12 is an exploded perspective view of a heel portion of a shoe according to a seventh embodiment of the present invention.

The heel portion 2 g of this embodiment includes a heel-tip portion 33 and a heel-base portion 34. The heel-tip portion 33 is replaceable, so it is unnecessary to replace the entire heel portion 2 g.

In addition, since it is possible to suppress “sink marks” at the time of molding the heel portion, the strength is increased when adhered as a unit. Note that, “sink marks” are a phenomenon in which a dents or holes are generated in a product when cooling the mold.

The heel-tip portion 33 has a joining surface 39 with the heel-base portion 34. The joining surface 39 is provided with a convex portion 35 and a rotation stopper (convex portion) 40, and the convex portion 35 is provided with a step portion 37. By providing the stepped portion 37, it becomes difficult for the convex portion 35 fitted in the concave portion 36 to become separated. The step portion 37 may be an O-ring.

The heel-base portion 34 has a joining surface 39′ with the heel-tip portion 33. The joining surface 39′ has a concave portion 36 and a rotation stopper (concave portion) 41, and cut grooves 38 are provided around the inside of the concave portion 36. By providing the cut grooves 38, it becomes easier to fit together the convex portion 35 and the concave portion 36.

Moreover, it is not illustrated in the FIG. 12, however, a gap, for example, may be provided to the extent that the tip-end section of a slotted screwdriver can be inserted into the end on the side of the portion where the heel-tip portion 33 and the heel-base portion 34 are joined. By inserting a slotted screwdriver into the gap, the joining surface 39 and the joining surface 39′ are separated so that it is easy to remove the heel-tip portion 33 from the heel-base portion 34.

By engaging the rotation stopper (convex portion) 40 and the rotation stopper (concave portion) 41, rotation of the heel-tip portion 33 with respect to the heel-base portion 34 can be prevented.

[First Manufacturing Method of the Present Invention]

FIG. 13 is an explanatory view of a manufacturing method for manufacturing a shoe according to an embodiment of the present invention.

The heel portion 2, the sole portion 3 and the upper portion 4 are each integrally molded by injection molding.

Injection molding is performed by injecting a hot melted synthetic resin into a hollow portion of a mold having cavities that are formed into the shapes of the heel portion 2, the sole portion 3 and the upper portion 4. The mold is cooled while applying pressure until the resin injected into the mold hardens.

As described above, when the mold is cooled, a deformation phenomenon of so-called “sink marks” occurs. Depending on the sink marks, there may be dents and holes in the product. Therefore, it is preferable to reduce the deformation as much as possible on the side having a decorative surface.

On the other hand, in this manufacturing method, cooling is performed from one side of the mold. The upper portion 4 h will be explained as an example.

In order to form the upper portion 4 h, a female mold 42 having a concave portion for forming the outer (back side) surface of the upper portion 4 h and a male mold 43 having a convex portion for forming the inner surface of the upper portion 4 h are used. When the female mold 42 and the male mold 43 are combined, a cavity portion having the shape of the upper portion 4 h is formed therebetween. After combining the female mold 42 and the male mold 43 and injecting the synthetic resin into the cavity portion, the synthetic resin of the upper portion 4 h is cooled from the female mold 42 side. As a result, it is possible to reduce the deformation of the outer (back side) surface of the upper portion 4 h. Less deformation on the decorative surface is advantageous for the shoe of the present invention comprising a hard material having transparency, color and gloss.

It should be noted that cooling only needs to be done from the mold on the front side of the product, regardless of being a male or female mold. For portions other than the upper portion 4 h as well, since the female mold generally becomes the outer surface of the heel portion or sole portion, cooling is performed from the mold that is in contact with these outer surfaces.

Moreover, sink marks are minimized by increasing the injection pressure.

For example, in the case of acrylic with a sole thickness of 15 mm, the following conditions may be applied.

Tonnage of the molding machine (required mold clamping force): 180 tons or more, and preferably 250 to 500 tons Injection pressure: 120 Mps or more at the maximum point, and preferably 150 to 200 Mps at the maximum point Injection dwelling force: Half or more of the above-described force, preferably more than 70% Molding time: 120 seconds or more, preferably 3 to 10 minutes Molding temperature: 200 to 240° C.

Although the above-described conditions are mainly for shoes for adults, in the case of shoes for children, for example, for infants, except for the molding temperature, it is preferable that the other values be ⅓ to ½ of the above-described values.

Molding shrinkage occurs in the process of cooling and solidifying the molten resin filled in the cavity, so particularly the resin to be crystallized produces relatively large molding shrinkage. The molding shrinkage ratio is determined by the interaction of many factors, and in general, the main factors are as follows.

-   -   1—Resin temperature     -   2—Mold temperature     -   3—Injection pressure     -   4—Injection speed     -   5—Injection time     -   6—Molded part thickness     -   7—Form and content of the filler and reinforcing agent

Here, regarding the sink mark problem arising from the “molded part thickness” in 6 above, it is possible to minimize the sink marks by raising the “injection pressure” in 3 above. Moreover, by controlling the “mold temperature” in 2 above by controlling the temperature difference, measures are taken to prevent sink marks from appearing on the outer peripheral surface.

Moreover, it can be said that in conventional products, together with eliminating sink marks in a product by making the wall thickness as constant as possible, attempts have also been made to make reduce the wall thickness to shorten the molding time, and increase the strength.

From such a fact, it can be said that manufacturing products with thick wall or with different wall thicknesses depending on the portion has been avoided. The product of the present invention aims at a seemingly carved product that has a thick and uneven wall thickness, and for which relieving the surface or the like has been performed. For example, when the thickness of the molded product exceeds 15 mm for an acrylic resin, a cooling time of about 20 minutes is required for cooling. Cooling of each mold is controlled to be during this cooling time.

Moreover, even after removal of the molded part, deformation is liable to occur due to internal heat. It is necessary to make a jig so that deformation does not easily occur, support the part to suppress deformation, or hold (method of placement) the part so that deformation does not easily occur.

In the sole portion, deformation is suppressed by placing the bottom of the outer heel portion 2 of the sole and the bottom portion near the metatarsal bone on a flat surface, and by using a jig provided with a support section for suppressing slack in (1) the toe direction in front of the metatarsal bone, and (2) in an intermediate position between the bottom of the heel portion 2 and the vicinity of the metatarsal bone. Depending on the thickness of the sole portion 3, it is possible to use only the support section of (2) above. In addition, in the case where the heel width is thick, the base of the heel tends to bulge sideways. Therefore, by holding the sole portion 3 with the heel portion 2 suspended, the horizontal bulging may be prevented.

In order to join the heel portion 2 and the sole portion 3 manufactured by injection molding, a convex ridge portion 46 is provided on the upper surface of the heel portion 2. The sole portion 3 and the upper portion 4 are joined at the peripheral edge portions of the sole portion 3 and the convex ridge portion 46. The convex ridge portion 46 will be further explained later.

In order to join the heel portion 2 and the sole portion 3, convex portions 44 are provided on the upper surface of the heel portion 2 and concave portions 45 are provided on the lower surface of the shoe sole portion 3. In the heel portion 2 and the sole portion 3, the convex portions 44 and the concave portions 45 are engaged, and the convex portions 44 and the concave portions 45 are integrally joined to each other at the joining surface.

FIG. 14A and FIG. 14B illustrate a joining method by the above-described convex ridge portion 46 and a modified example thereof.

In the example of FIG. 14A, the convex ridge portion 46 is provided on the inner side of the portion of the sole portion 3 joined to the bottom surface of the upper portion 4. When the sole portion 3 and the upper portion 4 are combined for joining, the convex ridge portion 46 comes into contact with the inner side of a joining portion of the upper portion 4. In other words, the bottom surface of the joining portion of the upper portion 4 abuts against the upper surface of the sole portion 3 in an abutting state, and the inner side surface of the bottom portion of the joining portion of the upper portion 4 comes in contact with the side surface of the convex ridge portion 46. As a result, the joining surface area is increased, and a firm bond can be obtained.

In the example of FIG. 14B, the convex ridge portion 46 is provided at a position corresponding to the bottom surface of the joining portion of the upper portion 4. The bottom surface of the joining portion of the upper portion 4 has a groove portion 47 to be engaged with the convex ridge portion 46. When the sole portion 3 and the upper portion 4 are combined for joining, the convex ridge portion 46 is fitted into the groove portion 47. The convex ridge portion 46 of the sole portion 3 and the groove portion 47 of the upper portion 4 are fitted to each other, whereby a firm bond can be obtained.

Note that it is preferable that the joining portion is transparent, and an adhesive containing methylene dichloride as a main component can be used. In addition, a cyanoacrylate instantaneous adhesive or a transparent epoxy resin adhesive may be used.

The joining method is not limited to adhesion but can be any known joining method such as thermal fusion or the like.

FIG. 15 illustrates a shoe 1 i in which a heel portion 2 and a sole portion 3 are integrally molded in advance, and a base portion 11 i is formed.

As illustrated in FIG. 15, the heel portion 2 and the sole portion 3 are integrally molded, and the upper portion 4 is joined to the upper surface thereof. Generally, since the base portion 11 i is suitable for integral molding, the manufacturing process can be simplified with this manufacturing method.

Note that in the example of FIG. 15, convex ridge portions 46 are provided, however the joining method is not limited thereto, and any joining method can be adopted.

Also, in the example of FIG. 15, a ribbon-shaped decoration 5 i is provided, however any decoration as described above can be provided.

[Second Manufacturing Method of the Present Invention]

FIG. 16 is an explanatory view showing another manufacturing method of a shoe according to the present invention.

According to this manufacturing method, a shoe 1 j includes half parts 50 j′ and 50 j″ vertically divided in the length direction of the shoe with each formed by integral molding. Dowels 49 and corresponding dowel holes are provided on the joining surfaces 48 of the half parts 50 j′ and 50 j″, respectively. At the time of joining, the dowels 49 are fitted with the dowel holes. As a result, it becomes difficult for the position to be displaced, and the bonding is strengthened.

An O-ring or a stepped portion may be provided on the dowels 49 and in the dowel holes, and the joining surfaces may be shaped to fit each other, and joined so as to be fitted to each other.

Note that concave portions 8 j for arranging the insole are provided in each of the half parts 50 j′ and 50 j″, and it goes without saying that the concave portions 8 j are also aligned with each other.

[Third Manufacturing Method of the Present Invention]

In a further manufacturing method of a shoe according to the present invention, only a heel portion 2 is not divided in half, however a sole portion and an upper portion are formed as half parts, and the heel portion is incorporated between both half parts and joined.

FIG. 17 is an explanatory view illustrating the present manufacturing method.

In a shoe 1 k, half parts 50 k′ and 50 k″ formed by vertically cutting a sole portion and an upper portion in the length direction of the shoe, and a heel portion 2 k are manufactured separately. The process of integrally molding and the cooling method are as described above.

The half parts 50 k′ and 50 k″ have cutout portions 51 in the lower part of the heel area. The cutout portions 51 have a T shape or an inverted triangular cutout shape such that a fitted member does not come out in a downward direction. The cutout portions 51 are provided to a predetermined depth from the half surfaces. In addition, dowels 49 k and corresponding dowel holes are provided on the joining surfaces of the half parts 50 k′ and 50 k″.

On the other hand, on the upper portion of the heel portion 2 k, a slide fitting portion 52 is provided, the vertical cross-sectional shape of which matches with the cutout shapes.

In this manufacturing method, first, the half parts 50 k′ and 50 k″ and the heel portion 2 k are integrally molded separately, after which the heel portion 2 k is arranged between the half parts 50 k′ and 50 k″, and the slide fitting portion 52 of the heel portion 2 k is slid into the cutout portions 51 of the half parts 50 k′ and 50 k″ and incorporated. After incorporating the heel portion 2 k, the half parts 50 k′ and 50 k″ are joined so that the dowels 49 k and the dowel holes are fitted with each other.

As a result, the shoe 1 k is formed with the heel portion 2 k incorporated. Since the cutout portions 51 are provided only up to a predetermined depth from the half surfaces, the slide fitting portion 52 of the heel portion 2 k cannot be seen from the outside. Note that the slide fitting portion 52 does not necessarily have to be a slidable shape. For example, it may be a spherical fitting portion. In that case, the cutout portions may be hemispherical cutout portions that sandwich the spherical shape from both sides.

Eighth Embodiment of the Present Invention

FIG. 18 illustrates a side view of a shoe 1 m with a coating 53 on the inner surface.

In the example of FIG. 18, the entire inner surface of the shoe 1 m is glossy. The gloss includes a glossy material that appears gold, silver, pearl or iridescent color. As the glossy material, a paint including a glittering powder called lame or glitter can be used, or a material such as shinning pearl using multi-layer reflected light could also be used.

The glossy material may be applied or may be attached to the inner surface of the shoe, or in addition to the above-described materials, a hologram sheet, a reflective sheet, or the like may be attached. In addition, gold or silver can also be deposited on the inner surface of the shoe 1 m by vapor deposition or sputtering.

Other than gloss, colors, patterns, and designs may be applied to the inner surface of the shoe. Since the shoe main body is transparent, it is possible to visually recognize the gloss, color, pattern, design or the like (hereinafter, referred to as gloss or the like) from the outside of the shoe, and the gloss or the like shine more beautifully by receiving light from the outside.

Moreover, since gloss or the like is applied to the inner surface of the shoe, even though the outer surface of the shoe may be damaged, the gloss surface or the like will not peel off.

The coating 53 may be applied to the entire inner side of the shoe, or it may be applied only to a part of the shoe.

In addition, as the coating 53, it is also possible to apply colors such as white, black or the like, or to mix these colors with gold, silver or pearl to give a glossy appearance. Moreover, a gold foil may be applied to the inside and a hermetic seal treatment may be performed thereon.

In addition to the coating 53 such as gloss or the like, rubber 54 or fur 55 can also be applied to the inner surface of the shoe. Alternatively, microfibers or the like may be implanted on the inner surface by electrostatic flocking or the like. This will be explained below.

The rubber 54 is a member having elasticity and flexibility, for example, natural rubber, isoprene rubber, chloroprene rubber, styrene butadiene rubber, and the like are suitable.

The rubber 54 may be provided on the inner surface of the shoe by double molding, a urethane material or a resin material including fibers may be applied to the inside of the shoe and the rubber 54 may provided on the inner surface of the shoe via that material. Since the shoe main body is transparent, it is preferable from an aesthetic viewpoint for the urethane material, the resin material including fibers, and the rubber 54 to have a color.

By applying the rubber 54 having elasticity and flexibility to the inside of the shoe, it is possible to absorb the pressure received by the foot during walking. Moreover, it is also possible to suppress sliding of the foot in the forward direction.

The rubber 54 may be applied to the entire inside of the shoe or may be applied only to a part thereof.

The fur 55 may be a real fur such as a rabbit fur, a fox fur, or the like, or a fake fur made of a chemical fiber. In any case, short hair is preferred because the fur 55 is applied to the inside of the shoe. The fur 55 is excellent in breathability and absorbing moisture, and is excellent for cold weather and heat retention, so is suitable for use on cold days.

The fur 55 may be attached to the inside of the shoe via the rubber 54, or only the hair portion of the fur 55 may be implanted directly on the inside of the shoe. The shoe main body is transparent, so by applying the fur 55 so that the front side thereof can be seen from the outside of the shoe, the appearance of the shoe becomes gorgeous.

Note that the fur 55 may be applied to the entire inside of the shoe or only partially.

Moreover, in order to give the appearance of bare feet from the outside, paint having a bare skin color (skin color, light orange color, wheat color, or the like) may be applied. Alternatively, the insole may be a bare skin color. In addition, in the toe portion, a toe decoration (pattern) may be applied to the inner surface, and in the nail portion, a nail decoration (pattern) may be applied on the inner surface. As a result, an appearance of bare feet is possible even in the case of wearing socks.

FIG. 19 illustrates a view of using of a shoe 1 m and a sock 56 according to an embodiment of the present invention, where the sock 56 is being worn inside the shoe 1 m.

By wearing the shoe 1 m and the sock 56 together in this embodiment, it is easy to adjust the size of the shoe, and it is possible to more properly fit the shoe on the foot. Particularly, in the case of a sock (foot sock, foot cover) shaped to open the part of the instep widely and cover the part of the foot that is in contact with the shoe, it is possible to wear the shoe without feeling discomfort on the outside of the foot.

In addition, by using a glossy material such as gold, silver, pearl or the like on the surface of the sock 56, the surface of the sock 56 glows when in contact with light, and reflected light is generated on the inner surface of the shoe 1 m, so light that is reflected and refracted by the surface is emitted from the surface.

As a result, this creates a sense of hardness of the shoes, and an emphasized glitter can be expressed.

Moreover, by applying a pattern or design on the surface of the sock 56, brings about a decorative effect and exhibits an aesthetic appearance when wearing the sock 56 together with the shoe 1 m. It should be noted that the sock 56 may also be formed from a lace material.

Ninth Embodiment of the Present Invention and Manufacturing Method Thereof

FIG. 20 and FIG. 21 are perspective views illustrating a shoe 1 n according to a ninth embodiment of the present invention and a manufacturing method thereof, and FIG. 22 is a partially enlarged view of FIG. 20.

Shoes are usually provided in standard sizes corresponding to foot lengths. Standard sized shoes have a determined foot girth for each size. Therefore, in the case where shoes selected according to the foot length are small for the wearer in foot girth, the wearer have to re-select shoes having a larger standard size though the re-selected shoes are big for the wearer in foot length, so shoes that are comfortable to wear cannot be obtained. Moreover, shoes selected according to foot length will also not be comfortable shoes in the case where the foot girth is too large for the wearer. Therefore, a plurality of shoes of different foot girths may be manufactured and provided for each foot length.

In the case where the upper portion of the shoe is formed of a soft member such as leather, there is a possibility that the upper portion will adapt to the foot as time elapses and the comfort will change. However, when the upper portion is formed of a hard member such as a synthetic resin or the like as in the case of the shoe of the present invention, such a change is unlikely to occur and it is necessary to make comfortable shoes from the beginning. Although it is conceivable to provide a plurality of shoes with different foot girths for each foot length, in the case of the shoes of the present invention, the upper portion is formed with a mold, so a plurality of molds having different foot girths or instep widths would need to be prepared for each standard size, which would increase the manufacturing cost. The shoe 1 n of this embodiment and its manufacturing method are intended to solve such problems.

The shoe 1 n includes a heel portion 2, a sole portion 3 provided on the heel portion, and an upper portion 4 n provided on the sole portion. The heel portion 2 and the sole portion 3 may be constituted by the above-mentioned integrally molded base portion 11 i, or may be configured according to the other examples described above.

The upper portion 4 n includes a main body portion 410 n and a rear portion 420 n molded separately from the main body portion 410 n. The main body portion 410 n is a main body of the upper portion 4 n excluding the rear portion, and includes a bump portion and a side portion. In the bump portion of the main body portion 410 n, the attachment portion 12 described above may be provided, and a decoration, for example, 5 i or the like may be attached.

The upper portion 4 n is combined with a base portion 11 i by the main body portion 410 n and the sole portion 3 being joined by a convex ridge portion 46 on the front end side and convex ridge portions 46 n on the sides provided on the peripheral portion of the upper surface of the sole portion 3. Since the joining with the convex ridge portions 46 n on the sides is similar to that of the above-described convex ridge portion 46, an explanation is omitted here. Like the above-described upper portion 4, groove portions to be fitted with these convex ridge portions may be provided on the bottom surface of the main body portion 410 n.

As illustrated in FIG. 21, in the shoe 1 n, first, the main body portion 410 n is joined to the sole portion 3. Next, an appropriate length of the rear portion 420 n is connected to the main body portion 410 n. Hereinafter, the main body portion 410 n and the rear portion 420 n will be explained in detail.

As illustrated in the figures, the main body portion 410 n has two main body side connecting portions 411 n at the rear end for connecting to the rear portion 420 n. The main body side connecting portions 411 n are thinner than the adjacent portions and are formed as thin wall portions. On the other hand, the rear portion 420 n has two rear portion side connecting portions 421 n at the front end for connecting with the main body portion 410 n. The rear portion side connecting portions 421 n are thinner than the adjacent portions and are formed as thin wall portions. The main body portion 410 n and the rear portion 420 n are connected by overlapping the main body side connecting portions 411 n and the rear portion side connecting portions 421 n in the thickness direction.

Here, as illustrated in the figures, the main body side connecting portions 411 n form outer steps with the adjacent portions, and the rear portion side connecting portions 421 n form inner steps with the adjacent portions, however the opposite is also possible. The main body side connecting portions 411 n and the rear portion side connecting portions 421 n are joined together to form a thickness corresponding to the adjacent portions, with one of the portions occupying about ⅓ to ⅔ of this thickness, and the other occupying ⅔ to ⅓. In other words, one of the main body side connecting portion 411 n and the rear portion side connecting portion 421 n form the inner surface of a connecting portion, and the other forms the outer surface of the connecting portion. The widths in the length direction of the main body side connecting portions 411 n and the rear portion side connecting portions 421 n are preferably equivalent, for example, about 5 mm to 25 mm, and preferably about 8 mm to 15 mm.

The main body side connecting portion 411 n may have a convex ridges 412 n along the height direction on the contact surface with the rear portion side connecting portion 421 n. In this case, a groove 422 n having a shape corresponding to the shape of the convex ridge 412 n is provided along the height direction on the contact surface with the main body side connecting portion 411 n of the rear portion side connecting portion 421 n. Note that a groove may be provided in the main body side connecting portion 411 n and a convex ridge may be provided in the rear portion side connecting portion 421 n. In addition, a plurality of convex ridges and grooves may be provided in a corresponding number. Moreover, although the convex ridge and groove illustrated in the figure are provided over the entire height direction, they may be provided in a part thereof.

In order to manufacture the shoe 1 n, molds having cavities formed in the shapes of the base portion 11 i, a main body portion 410 n, and a rear portion 420 n are respectively prepared. Here, in order to manufacture the rear portion 420 n having different lengths, a plurality of molds are prepared for the rear portion 420 n of which the shapes of the rear portion side connecting portions are the same however the overall lengths of the rear portions are different. Then, these molds are set in an injection molding machine, and synthetic resin is injected and cooled to form the base portion 11 i, the main body portion 410 n, and the plurality of rear portions 420 n, respectively.

Next, when the main body portion 410 n and the base portion 11 i are assembled and the rear portion 420 n having an appropriate length is connected to the main body portion 410 n, the shoe 1 n is completed. An adhesive may be used to connect the main body side connecting portions 411 n and the rear portion side connecting portions 421 n.

As described above, in the shoe 1 n according to this embodiment, the rear portion 420 n is formed separately from the main body portion 410 n of the upper portion 4 n, and a plurality of rear portions 420 n that are connectable to the main body portion 410 n and that have different lengths are formed. As a result, the main body portion 410 n of the upper portion is selected according to the foot girth, and the foot length can be dealt with by connecting the rear portion 420 n having an appropriate length, so comfortable shoes of which both the foot length and the foot girth are matched to the wearer can be provided at a low manufacturing cost. The connection of the rear portion to the main body portion may be performed at the manufacturing factory, or may be carried out by adjusting the shoes to match the feet of the wearer at a shoe store.

Note that in the above description, an example was explained in which in the upper portion 4 n, the main body portion 410 n includes a bump portion and side portions, and the rear portion 420 n includes only the rear portion, however, the main body portion 410 n may include only the bump portion, and the rear portion 420 n may include the side portions and the rear portion. Alternatively, the main body portion 410 n may include the bump portion and a part of the side portions, and the rear part 420 n may include a part of the side portions and the rear portion. Particularly, the foot girth may greatly influence the size of a shoe, so it is more effective to provide connecting locations at positions 20 mm to 60 mm behind from the location serving as the reference for foot girth measurement.

Note that in the above description, it is also possible to prepare a plurality of molds for the base portion 11 i having different lengths and to form a plurality of base portions 11 i having lengths corresponding to foot lengths that include the rear portion 420 n. Alternatively, the sole portion 3 and the heel portion 2 may be molded separately. In this case, a plurality of molds are prepared for sole portions 3 for forming a plurality of sole portions 3 corresponding to foot lengths that include the rear portion 420 n, however, only one mold should be prepared for the heel portion 2.

Tenth Embodiment of the Present Invention and Manufacturing Method Thereof

FIG. 23 is a perspective view illustrating a shoe 1 p according to a tenth embodiment of the present invention and a manufacturing method thereof, and FIG. 24 is a partial enlarged view thereof. Only an upper portion 4 p of the shoe 1 p differs from the ninth embodiment.

The upper portion 4 p includes a main body portion 410 n, a rear portion 420 n formed separately from the main body portion 410 n, and a spacer 440 p formed separately from the main body portion 410 n and the rear portion 420 n. Hereinafter, the explanation will center on differences from the ninth embodiment.

In the upper portion 4 p, by providing a plurality of convex ridges 412 n on the main body side connecting portion 411 n and connecting a groove 422 n on the rear portion side connecting portion 421 n with a specified convex ridge 412 n of the plurality of convex ridges 412 n, the connecting position (engagement positions) between the main body portion 410 n and the rear portion 420 n is varied in the length direction. As a result, the connecting length L, which is the distance between the front end of the main body side connecting portion 411 n and the rear ends of the rear portion side connecting portions 421 n, varies. For example, in a first connecting position where the groove 422 n and the front convex ridge 412 n are engaged, the connecting length L becomes short, and as shown in the figure, in a second connecting position where the groove 422 n and the rear convex ridge 412 n are engaged, the connecting length L becomes long. As illustrated in the figure, the number of the convex ridges 412 n may be two, three, even four or more. Moreover, except for the case where the front end of the rear portion side connecting portion 421 n is in contact with the front end of the main body side connecting portion 411 n, a gap 430 p is formed on the outer surface between the front end of the rear portion side connecting portion 421 n and the front end of the main body side connecting portion 411 n. The width tin the length direction of the gap 430 p varies according to the connecting length L.

The spacer 440 p is for fitting into the gap 430 p, and the shape of the spacer 440 p corresponds to the shape of the gap 430 p. In addition, the spacer 440 p has an outer surface similar to an adjacent portion of the main body portion 410 n and an adjacent portion of the rear portion 420 n. For example, in the case where these outer surfaces have a reflecting plane, the outer surface of the spacer 440 p also has a reflecting plane. The number of the spacers 440 p corresponds to the variation of the width t of the gap 430 p, and in the case where the gaps 430 p are formed in a pair as shown in the figure, the number corresponds to the pair. Note that configuration may be possible in which in the case where the groove 422 n is in the first connecting position where it engages with the front convex ridge 412 n, the spacer 440 p is not fitted. In this case, it is desirable that the adjacent portion of the main body side connecting portion 411 n of the main body portion 410 n and the adjacent portion of the rear portion side connecting portion 421 n have outer surfaces that coincide.

Note that the upper portion 4 p may be configured by providing a plurality of grooves in the main body side connecting portion 411 n, providing a convex ridge on the rear portion side connecting portion 421 n, and connecting the convex ridge with a specified groove of the plurality of grooves, whereby the connecting position (engagement position) between the main body portion 410 n and the rear portion 420 n may be varied in the length direction.

In the shoe 1 p, it is sufficient to prepare a plurality of molds for the spacers 440 p according to the width t of the gap 430 p for each main body portion 410 n, and prepare only one mold for the rear portion 420 n. Then, the main body portion 410 n and the rear portion 420 n are selected according to the foot girth, and the foot length can be dealt with by adjusting the connecting length L. The spacer 440 p having an appropriate width t may be fitted in the gap 430 p in the outer surfaces that occurs due to adjusting the connecting length L. As a result, comfortable shoes can be provided at an even lower manufacturing cost.

Note that those skilled in the art may conceive additional effects and various modifications of the present invention on the basis of the above description, however aspects of the present invention are not limited to the above-described embodiments. Various additions, modifications and partial deletions are possible without departing from the conceptual idea and gist of the present invention derived from the contents defined in the appended claims and their equivalents. 

What is claimed is:
 1. A shoe comprising: a heel portion; a sole portion provided on the heel portion; and an upper portion provided on the sole portion; wherein the heel portion and the sole portion are made almost entirely of an organic glass; and the upper portion is made almost entirely of an organic glass.
 2. The shoe according to claim 1, wherein the shoe has a plurality of reflective planes (facets) on at least a part of the surface thereof.
 3. The shoe according to claim 1, wherein at least part of the sole portion and the inside of the upper portion is provided with an insole having a cushioning property to compensate for a gap generated between the shoe and a foot of a wearer.
 4. A manufacturing method of the shoe according to claim 1, comprising: a step of integrally molding the heel portion and the sole portion with a synthetic resin; a step of integrally molding the upper portion with a synthetic resin; and a step of joining the upper portion with the heel portion and the sole portion that are integrally molded.
 5. A manufacturing method of the shoe according to claim 1, comprising: a step of integrally molding the heel portion and the sole portion with a synthetic resin; a step of molding the rear portion of the upper portion with a synthetic resin; a step of molding a main body portion that is a portion other than the rear portion of the upper portion with a synthetic resin; a step of joining the main body portion of the upper portion with the heel portion and the sole portion that are integrally molded; and a step of connecting the rear portion to the main body portion. 